Measurement of power distribution network (PDN) Z-parameters and S-parameters of a programmable logic device (PLD), such as field programmable gate array (FPGA) or complex programmable logic device (CPLD), is performed by configuring and using only logic blocks and I/O blocks commonly available in any existing programmable logic device, without the need of built-in dedicated circuits. The measured models include the PDN elements on the PLD die, PLD package, and PCB. The S-parameter and Z-parameter models can be then used in circuit simulation tools to evaluate the power supply noise in the PLD logic core and the timing jitter in the PLD I/O data links.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method for measuring the phase of periodic variations of the voltage of a power supply domain of a programmable logic device containing configurable blocks powered from the power supply domain, comprising: configuring the programmable logic device to implement a current load generator that consumes a periodic varying electric current from a power supply domain the said periodic varying electric current having an activate feature and a frequency programming feature; configuring the programmable logic device to implement a ring oscillator containing configurable blocks powered from said power supply domain; configuring the programmable logic device to implement a phase and phase modulation measurement function for said ring oscillator; programming a frequency value of said periodic varying electric current, activating said periodic varying electric current, measuring the phase and phase modulation of said ring oscillator, calculating the phase of the voltage variation of the power supply domain by computations including the measured phase and phase modulation of said ring oscillator.
2. The method of claim 1 wherein the current load generator divides the period of the varying electric current into a plurality of time intervals and generates phase signals for each time interval, the phase and phase modulation measurement function uses said phase signals to count the number of said ring oscillator oscillation periods within each time interval, the phase of the voltage variation of said power supply domain is determined from the distribution of the counted numbers within the time intervals corresponding to a period of the varying electric current.
3. The method of claim 1 further comprising the step of: calculating the Z11 parameter of the power supply domain by computations that include the phase of the voltage variation of the power supply domain.
4. The method of claim 3 further comprising the step of: repeating the steps of claim 1 for multiple said programmed frequency values of the periodic varying electric current to provide a plurality of Z11 parameters corresponding to each programmed frequency value.
5. The method of claim 4 further comprising the step of: converting the Z11 parameters into S11 parameters and creating an s-parameter model of the power distribution network of said power supply domain.
6. A method for measuring the phase of a periodic variation of the voltage of one or more power supply domains of a programmable logic device containing configurable blocks powered from the power supply domains, comprising: configuring the programmable logic device to implement a first current load generator that consumes a first periodic varying electric current from a first power supply domain the said first periodic varying electric current having an activate feature and a frequency programming feature; configuring the programmable logic device to implement a second current load generator that consumes a second periodic varying electric current from a second power supply domain the said second periodic varying electric current having an activate feature and a frequency programming feature; configuring the programmable logic device to implement a first ring oscillator containing configurable blocks powered from the first power supply domain; configuring the programmable logic device to implement a second ring oscillator containing configurable blocks powered from the second power supply domain; configuring the programmable logic device to implement phase and phase modulation measurement functions for the ring oscillators; programming a frequency value of said first periodic varying electric current, activating said first periodic varying electric current, measuring the phase and phase modulation of the first ring oscillator, deactivating said first periodic varying electric current, calculating the phase of the voltage variation of the first power supply domain by computations including the measured phase and phase modulation of the first ring oscillator; calculating the Z11 parameter of the first power supply domain by computations that include the phase of the voltage variation of the first power supply domain; programming a frequency value of said first periodic varying electric current, activating said first periodic varying electric current, measuring the phase and phase modulation of the second ring oscillator, deactivating said first periodic varying electric current, calculating the phase of the voltage variation of the second power supply domain by computations including the measured phase and phase modulation of said second ring oscillator; calculating the Z21 parameter of the second power supply domain by computations that include the phase of the voltage variation of the second power supply domain; programming a frequency value of said second periodic varying electric current, activating said second periodic varying electric current, measuring the phase and phase modulation of the first ring oscillator, deactivating said second periodic varying electric current, calculating the phase of the voltage variation of the first power supply domain by computations including the measured phase and phase modulation of the first ring oscillator; calculating the Z12 parameter of the first power supply domain by computations that include the phase of the voltage variation of the first power supply domain; programming a frequency value of said second periodic varying electric current, activating said second periodic varying electric current, measuring the phase and phase modulation of the second ring oscillator, deactivating said second periodic varying electric current, calculating the phase of the voltage variation of the second power supply domain by computations including the measured phase and phase modulation of the second ring oscillator; calculating the Z22 parameter of the second power supply domain by computations that include the phase of the voltage variation of the second power supply domain.
7. The method of claim 6 further comprising the step of: repeating the steps of claim 6 for multiple said programmed frequency values of the periodic varying electric current to provide a plurality of Z parameters corresponding to each programmed frequency value.
8. The method of claim 7 further comprising the step of: expanding the steps of claims 6 - 7 to a plurality of N power supply domains for each power supply domain calculating the network parameters Zpq where 1=<p=<N and 1=<q=<N.
9. The method of claim 7 further comprising the step of: converting the Z parameters into S parameters and creating an S-parameter model of the programmable logic device power distribution network.
10. The method of claim 6 wherein the current load generator divides the period of the varying current into a plurality of time intervals and generates phase signals for each time interval, the phase and phase modulation measurement function uses said phase signals to count the number of ring oscillator oscillation periods within each time interval, and the phase of the voltage variation of said power supply domain is determined from the distribution of the counted numbers within the time intervals corresponding to a period of the varying electric current.
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June 15, 2018
February 11, 2020
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